easy;
you need to remove the knobs,front panel etc.
remove the heater contorl assembly carefully and remove the 2 wiring multi plugs altogether
switch ignition on and then turn it off
reconnect multi-plugs,refit control unit and its facia.dials etc

I had the same problem as the initial poster and the solution worked for me. I prized the surround away but did not need to remove the dials. Not sure they could come off! Then just four torx screws and the controls are out. Simples. Thanks daddyfixit.